Power assembly

ABSTRACT

A power assembly is formed from dual rotary internal combustion engine units joined along a common output shaft. Each engine includes a plurality of swinging arms spaced uniformly in a rotor chamber with a rotor on the output shaft engaging the arms in the housing to control and exhaust strokes, and inward power strokes of each of the arms. Each arm includes an outwardly tapered, wedge-shaped horn member engageable within a recess provided in the adjacent engine housing to define an expandable compression chamber between the housing and each arm and to permit the arms to move freely between the inward and outward positions. The rotor chambers are angularly offset relative to one another to effect a corresponding offset of the arms of each engine and the compression chambers associated with one rotor chamber are coupled to the combustion chambers associated with the other rotor chamber. Thus, the power impulses produced in one of the rotor chambers are offset with respect to the power impulses produced in the other rotor chamber to effect a smooth and continuous transmission of torque to the common shaft. Further features are disclosed.

United StateS Patent [1 1 Hinckley [451 Nov. 20, 1973 POWER ASSEMBLY [75] Inventor: John N. llinckley, Beloit, Wis.

[73] Assignee: Beloit College, Beloit, Wis.

[22] Filed: May 8, 1972 21 Appl. No.: 251,267

Related US. Application Data [62] Division of Ser. No. 870,331, Sept. 24, 1969, Pat.

[52] US. Cl. 123/8.41, 123/823 [51] Int. Cl. F02b 53/08 [58] Field of Search 123/827, 8.23, 8.07,

[56] References Cited UNITED STATES PATENTS 2,500,458 3/1950 l-linckley 123/827 2,060,937 11/1936 Hinckley et a1....

1,341,854 6/ 1920 Kline 3,361,119 1/1968 Foxley-Conolly 123/823 Primary Examiner-Carlton R. Croyle Assistant ExaminerMichael Koczo, Jr. Attorney-Hume, Clement, Brinks, William, Olds & Cook [5 7] ABSTRACT I A power assembly is formed from dual rotary internal ber between the housing and each arm and to permit the arms to move freely between the inward and outward positions. The rotor chambers are angularly offset relative to one another to effect a corresponding offset of the arms of each engine and the compression chambers associated with one rotor chamber are coupled to the combustion chambers associated with the other rotor chamber. Thus, the power impulses produced in one of the rotor chambers are offset with respect to the power impulses produced in the other rotor chamber to effect a smooth and continuous transmission of torque to the common shaft. Further features are disclosed.

4 Claims, 8 Drawing Figures Pm m nuuvzo mm 23773021 sum 2 or 6 PAIENTEUNUV 20 ms 3773;021

sum as? 6 FIG. 7

POWER ASSEMBLY CROSS-REFERENCE TO RELATED APPLICATION This application is a division of application Ser. No. 870,331, filed Sept. 24, 1969, now US Pat. No. 3,660,978, and assigned to the same assignee as the present invention.

BACKGROUND AND GENERAL DESCRIPTION As well known to those skilled in the art, the recipro-- eating internal combustion engines in current use have many inherent disadvantages. For instance, such engines have generally low thermal efficiency resulting mainly from the inability of the engine to fully utilize the energy in the fuel. Moreover, such engines generally have extremely poor pollutant emission character- 4 istics, since the fuel is not burned completely within the engine combustion and expansion chamber before it is exhausted to the atmosphere. The overall mechanical efficiency of reciprocating piston engines is also low, in the range of 25 percent, due to such factors as the inability of the pistons to produce power for the first 30 and last 40 of each stroke; the requirement of having two complete piston cycles to produce one power stroke in a four-cycle piston engine; and the need for power-absorbing static and dynamic counterbalancing and parasitic auxiliary systems.

Previous attempts to improve upon the thermal and mechanical characteristics of reciprocating piston engines have met with varying degrees of success. Reciprocating engine designs continue to require expensive fuels, continue to have unacceptably high pollution characteristics, and involve complicated structural arrangements which are expensive to manufacture, operate, and maintain, and which have unsatisfactorily low mechanical efficiency.

The present invention overcomes the abovementioned problems incident to making and using reciprocating piston engines by providing a power assembly composed of which pair of improved rotary internal combustion engines, each of whic is capable of operating with substantially improved mechanical and thermal efficiencies and which has greatly enhanced antipollution characteristics. Improved thermal efficiency and reduced pollutant emissions are possible because of the structural and functional characteristics of the dual rotary enginewhich permit more complete combustion of the air-fuel mixture during the operation of the engine. The invention also allows expansion of the combustion gases to a condition approaching atmospheric pressure, or about twice the volume possible in conventional piston engines. Similarly, the engine requires no crank case, and hence will create no crank case emissions. Improved mechanical efficiency results from the structural and functional features of the present invention which cause the smooth and continuous flow of power to an output shaft, with a high horsepower to weight ratio. The power assembly also is capable of producing high torque at low speeds, and has a great flexibility of operation.

EXEMPLARY EMBODIMENTS Additional objects and features of the present invention will become apparent from the following description of several exemplary embodiments, wherein standard engine components, such as the carburetor, the throttling mechanism and the like, have been omitted for sake of clarity.

In the drawings:

FIG. 1 is a partial sectional end view of an engine assembly of the present invention formed from multiple engine units which are joined to a common output shaft in a dynamically balanced relationship;

FIG. 2 is a sectional side elevational view of the multiple-unit engine assembly as viewed along the line 22 in FIG. 1;

FIG. 3 is a sectional end view of a modified engine assembly incorporating dual engine units which are joined to a common drive shaft in a balanced relationship, with the chambers of the engines cross-coupled;

FIG. 4 is a sectional side elevational view of the dual cross-coupled engine assembly as viewed along the line 44 in FIG. 3;

FIG. 5 is a partial sectional end view of an engine assembly in accordance with this invention which incorporates dual cross-coupled engine units wherein each of the engines includes a double-lobe rotor and four wedge-shaped swinging abutment arms;

FIGS. 6A and 6B are joined sectional side elevational views of the engine assembly illustrated in FIG. 5, as viewed along the section lines 6A--6A and 6B-6B, respectively;

FIG. 7 is a partial sectional end view of the dual engine shown in FIGS. 5 and 6, illustrating a cam start-up mechanism for each engine unit in the dual engine assembly.

MULTIPLE UNIT ENGINE ASSEMBLY lobe rotor 150. Modified transfer housings 370 permit the separate units 300A and B to be joined rigidly together along the shaft 330.

As indicated in FIG. 1, the units 300A and B are joined on the shaft 330 so that the rotors and arms of the units are in static and dynamic balance. The need for any massive counterbalancing means for the assembly 300 is thereby eliminated. Since the illustrated engine assembly 300 comprises two units 300A and B, the rotors 150 in the units are fixed to the common shaft 330 so as to be 180 out-of-phase. Further, the rotor housings for the units 300A and B are arranged so that the swinging arms A-C for the unit 300A (shown in solid lines in FIG. 1) are oriented 60 out-of-phase with the corresponding arms l40-C on the other engine unit 3008 (as shown in broken lines in FIG. 1). The engine units 300A and B are thereby arranged in static and dynamic balance.

During the operation of the assembly 300, each engine unit 300A and B operates in the same manner as the described engine of the aforesaid parent application. However, due to the out-of-phase orientation of the plurality of arms 140A-C on the units 300A and 300B, the arms will operate to transmit a power impulse to the common shaft 320 for each 60 of revolution of the shaft. The assembly 300 hence can be controlled by common ignition and throttling means to function as the equivalent of a conventional twelve cylinder, four-cycle piston engine, with six power impulses to the rotors 150 per shaft revolution. Furthermore, it is apparent from the above description that the assembly 300 can be formed from a selected even or odd number of engine units which are joined in a balanced fashion along the common shaft 320. The assembly 300 in accordance with this invention thus has great flexibility and can be adapted to suit the horsepower, power impulse frequency, and space requirements of a variety of special industrial applications.

MULTIPLE UNIT ENGINE ASSEMBLY CROSS-COUPLED FIGS. 3 and 4 illustrate an additional engine assembly 400 in accordance with this invention. The assembly 400 comprises dual engine units 400A and B which are joined to a common drive shaft 430 in crosscoupled relationship. Each of the units 400A and B is similar in construction to the engine the engine described in the aforesaid parent application. Modified transfer housings 470A and B are adapted to rigidly secure the units 400A and B together and to cross-couple the compression and combustion chambers of the two units. described in the aforesaid parent application. Modified transfer housings 470A and B are adapted to rigidly secure the units 400A and B together and to cross-couple the compression and combustion chambers of the two units.

The single-lobe rotors 450A and B included in the engine units 400A and B, respectively, have the same construction as their counterparts in the single engine structure disclosed and claimed in the cited parent application. As indicated in FIG. 4, these rotors 450A and B are joined to the common shaft 430 in an axially aligned relationship. The engine flywheels 163 offset the mass of these aligned rotors 450A and B and maintain the engine assembly 400 in static and dynamic balance during operation. This alignment for the rotors 450A and B permits the cross-coupled engine units 400A and B to operate in the proper sequence.

Each of the engine units 400A and B also includes three swinging abutment arms 440A-C and 440D-F, respectively, which are uniformly positioned around the shaft 430. The construction of each of these arms 440A-F is similar to the construction of the corresponding arms of the single engine assembly of the parent application. The unit 400A is positioned on the shaft 430 so that the arms 440A-C (shown in solid lines in FIG. 3) are 60 out-of-phase with the arms 440DF of the unit 400B (shown in broken in FIG. 3). This arrangement places the combustion chambers 125A-C and 125D-F of the engine units 400A and B, respectively, in axial alignment with the valve assemblies 200A-F and the connected compression chambers 124 of the opposite engine unit. In addition, the modified transfer housings 470A and B, as shown in FIG. 4, define fluid-tight transfer passages 435 between these aligned combustion and compression chambers. Hence, the compression chambers 124 in each engine unit 400A and B are in direct fluid communication with the combustion chambers 125 in the opposite unit through short and substantially straight fluid passages which minimize internal fluid losses in the engine assembly 400. The short transfer passages 435 will further reduce the travel time and the velocity of the airfuel charges during the transfer of the charges from the compression chambers 124 to the combustion chambers 125.

In operation, the engine assembly 400 is started by cranking the flywheels 163 in the conventional manner so that the cam trucks 169 engage with the cam rollers 168. As described with respect to the single engine disclosed and claimed in the parent application, the tracks 169 will positively drive the arms 440A-F sequentially inward and thereby draw charges of air-fuel mixture into the associated compression chambers 124 through the intake channels 132. The continued rotation of the rotors 450A and B induced by the inertia of the flywheels 163 will then force the arms 440-F sequentially outward and compress the air-fuel charges.

After a selected gas pressure is reached in the compression chambers 124, further outward movement of the arms 440A-C will open the valve assemblies 200A-F and transfer the compressed air-fuel charges into the connected combustion chambers 125 through the direct transfer passages 435. More specifically, the charge compressed in the chamber 124 adjacent the arm 440A is transferred to the combustion chamber 125D adjacent the arm 440D; the charge compressed by the arm 440B is transferred to the combustion chamber 125E adjacent the arm 440E; and the charge compressed by the arm 440C is transferred to the combustion chamber 125F adjacent the arm 440F. Thus, the charges of air-fuel mixture compressed by the arms 440A-C of the engine unit 400A are transferrred for ignition and expansion into the combustion chambers 125 of the other engine unit 4008. The compression chambers 124 in the engine unit 400B are similarly connected by the transfer channels 435 to the axially aligned combustion chambers 125A-C in the opposite unit 400A. Specifically, the charge compressed by the arm 440D is transferred to the combustion chamber 125C associated with the arm 440C; the charge compressed by the arm 440E is transferred to the chamber 125A adjacent the arm 440A; and the charge compressed by the arm 440F is transferred to the combustion chamber 125Badjacent the arm 440B.

After the transfer of the compressed charges occurs in the above-described manner, the charges are sequentially ignited in the combustion chambers 125 by the spark plugs 126. The charges will then expand sequentially against the associated arms 440A-F and rotors 450A or B and thereby transmit a substantial torque force to the output shaft 430. As described in detail in connection with FIGS. 1-8 of the parent case, the rotors 450A and B, the arms 440A-F and the exhaust ports are arranged to overlap the expansion of the charges against the rotor and the adjacent arms (for instance, the arms 440A and B in the unit 400A and the arms 440D and E in the unit 4003), so that the flow 'of torque to the shaft 430 is smooth and continuous.

Furthermore, the assembly 400 is timed so that the combustion chambers 125 remain closed by the associated arm for an additional 45 to 60 of rotor rotation after the air-fuel charges are ignited by the spark plugs 126. This arrangement permits substantially complete combustion of the air-fuel charges in the spherical combustion chambers 125 before the charges are released for expansion into the rotor housing 120, and thereby substantially reduces the pollutant emissions of the assembly 400. The fully expanded charges are then exhausted from the rotor housing 120 through the exhaust ports 190 in the same manner as described above with respect to the engine 100.

MULTIPLE UNIT ENGINE ASSEMBLY DOUBLE LOBE ROTORS cal in construction and are cross-coupled together about a common shaft 530. In accordance with this invention, the individual engine units 500A and B include double lobe rotors 550A and B, respectively, which are arranged in axial alignment on the common shaft 530. Furthermore, the units 500A and B each include four uniformly spaced swinging abutment arms 540A-D and 540E-l-l respectively.

Referring to FIGS. 5 and 6 in more detail, the section 6A6A in FIG. 5 is a section taken in the engine unit 500A, and the section 63-68 is a section taken in the unit 500B. Both such sections are illustrated in FIG. 6. Each of the engine units 500A and B includes a rotor housing 520 which surrounds the central shaft 530 and provides a generally cylindrical chamber for the associated rotor 550A or B. As shown in FIG. 6, the housings 520 are machined to have substantially the same width as the swinging arms 540 and the rotors 550. The ends of the engine assembly 500 are closed by flywheel housings 560 and 570. Suitable bearings 571 support the common shaft 530 centrally disposed in these housings. The housings 560 and 570 define machinedend plates 562 and 572, respectively, which seal the adjacent ends of the engine assembly 500.

The assembly 500 also includes a central transfer housing 575 which is mounted on the shaft 530 so as to seal the interior of the engine units 500A and B from each other. The housing 575 defines machined face plates 576. These housings 560, 570 and 575 include apertures for receiving suitable head bolts and gasketing material (not shown) to join the housings together in sealed relationship and for supporting the pivot pins 541 (FIG. 5) of the swinging abutment arms 540A-I-I.

As shown in FIGS. 6 and 7, the housings 560 and 570 incorporate flywheels 563 for cranking the engine assembly 500. Further, a cam track 569 is provided on the flywheels 563 for engaging with cam follower rollers 568. As described in detail in FIGS. l-8 of the parent case, the rollers 568 are joined to the adjacent arms 540A-H by levers 567A-H, respectively. The cam tracks 569 will operate through the levers 567 and rollers 568 to sequentially drive the arms 540A-I-I inwardly when the flywheels 563 are cranked.

More specifically, as seen in FIG. 7, the cam track 569 on each flywheel 563 includes a pair of diametrically opposed cam lift portions 569A which lift the rollers 568 and drive the connected armsr540 inwardly against the associated rotor 550. A pair of diametrically opposed first dwell portions 569B on each track 569 follow the lift portions 569A and engage the roller 568 to allow the arms 540 to remain inward for a selected time period. A pair of opposed release portions 569C on the tracks 569 then release the rollers 568 so that the rotors 550 can drive the associated arms 540 outwardly. Finally, a pair of opposed second dwell portions 569D on the tracks 569 allow the arms 540 to remain in an outward position for a selected time period.

As also described in detail in the present case, the cam tracks 569 are arranged to clear the rollers 568 during the normal operation of the engine assembly 500, and to engage with the rollers 568 during engine start-up or misfire. The arm movement induced by the tracks 569 will hence draw in an initial charge of airfuel mixture into the compression chambers of the assembly 500.

As indicated in FIGS. 5 and 6, the rotors 550A and B are connected to the common shaft 530 by keys, and the arms 540A-I-I are similarly mounted on the pivot pins 541. This arrangement mounts the arms 540A-H and the rotors 550 within the rotor housings 520 in a free floating relationship, so that the rotors and arms can shift laterally within the housings during the operation of the assembly 500. The free-floating rotors 550 and arms 540 can hence be sealed against the plates 562, 572 and 576 by means of labyrinth sealing grooves 521 provided on the side portions of the arms and the rotors.

The labyrinth grooves 521 are short and discontinuous, and are arranged in an unaligned orientation which follows the general profile of the associated arm or rotor. Each of the labyrinth grooves 521 thus functions as a check valve to substantially stop the flow of gas past the arms or rotors adjacent the plates 562, 572, and 576 of the assembly 500. The effectiveness of the seal created by the grooves 521 is enhanced by selecting the materials for the rotors, arms, and housings to have substantially equal coefficiencies of expansion. The clearance between the rotor, arms and end plates described above will hence be substantially constant regardless of the load oroperating temperature of the engine assembly 500.

The swinging abutment arms 540A-H are identical in construction. As illustrated in solid lines in FIG. 5, four of the arms 540A-D are uniformly spaced in the engine unit 500A around the associated rotor 550A. As shown by the broken lines in FIG. 5, the other four arms 540E-H are uniformly spaced about the rotor 5508 within the engine unit 5003. Further, the engine units 500A and B are offset 0n the shaft 530 so that the four arms 500A-D are'45 out-of-phase with the other four arms 540A-H. As also illustrated in FIG. 5, the rotors 550A and B are joined to the shaft 530 in an axially aligned relationship. Such orientation for the rotors 550 and arms 540 permits the engine units 500A and B to operate jointly in the assembly 500 to produce a smooth and continuous application of torque to the output shaft 530.

The free end of each of the swinging arms 540A-H includes a bevelled contact surface 543 for engaging with and sealing against the periphery of the associated rotor 550 during the inward power stroke of the arm. Further, each arm 540 includes a machined inner surface 544 adapted for engaging with the periphery of the associated rotor 550 as the rotor returns the arm outwardly after the power stroke is completed. A projection 546 on each arm defines the point closest to the associated pivot pin 54] at which the associated rotor 550 will engage the arms. A relief portion 547 on each arm allows the rotors 550 to engage with the projections 546. The projection 546 thereby causes the rotor 550 to contact the arms at a point of substantial leverage which is remote from the pivot pins 541. Suitable sealing strips (not shown) may be provided on the arms 540 to seal the compression, combustion and expansion chambers of each engine unit 500A and B from each other.

In accordance with this invention, each of the arms 540A-H has front and rear edges 581 and 582 respectively, which converge to provide each arm with an integral projecting horn member 580 which extends outwardly from the arm. The front edge 581 of each arm is arcuate and generally concentric with the associated pivot pin 541 and extends outwardly for a length exceeding the predetermined distance of the inward arm stroke. The front edge 581 is also spaced, as indicated in FIG. 5, so as to define a flat contact surface 549 at the free end of each of the arms for receiving the force of the expanding combustion gases during the operation of the engine assembly 500. The rear edge 582 of each arm is generally straight and seats against an adjacent straight surface on the associated engine housing 520. This arrangement provides each horn 580 with a substantial wedge-shaped configuration which allows the arms 540 to include a substantial number of labyrinth sealing grooves 521, and thereby enhances the seal between the arms and the rotor housings. The wedge-shaped configuration of the horns and arms also prevents the formation of any substantial vacuum force outside of the arms which would inhibit arm movement.

As shown in FIG. 5, the rotor housings 520 include a plurality of uniformly spaced horn recesses 522. The recesses 522 are shaped to conform closely to the horns 580 and will thereby receive the adjacent born when the associated arm 540A-H is in its outermost position. Further, each of the horn recesses 522 includes an arcuate forward edge 523, which, like the front edge 581 on the associated horn 580, is concentric with the arm pivot pin 541. The horn edge 581 therefore will slide in substantially sealed relationship with the adjacent recess edge 523 as the arm 540 moves inward. Since the length of the horns 580 exceeds the length of the inward stroke of the arms 540, the horns will remain in sealed relationship with the housing 520 along this forward edge 523 throughout the operation of the engine.

Thus, the horn recess 522 outside of each of the arms 540A-H defines a sealed expandable compression chamber, which increases in volume as the associated arm moves inward and reduces in volume as the arm moves outward. Charges of air-fuel mixture hence can be drawn into these compression chambers 522 by the inward movement of each arm, and compressed by the subsequent outward movement of the arm. The wedgeshaped configuration of the horns 580 prevents the development of a partial vacuum within the compression chambers 522 which would otherwise present a drag on the swinging arms 540.

The engine units 500A and B in the assembly 500 are also provided with uniformly spaced combustion chambers 525A-H and spark plugs 526. As illustrated in FIG. 5, the four combustion chambers 525A-D are formed in the engine unit 500A so that one combustion chamber is positioned outwardly from the free end of each of the arms 540A-D, Similarly, the four combustion chambers 525E-H are formed in the engine unit 5008 so that one chamber is spaced adjacent the free end of each arm 540E-H. Outlet channels 527 lead from the chambers 525 to the interior of the rotor housing 520 at a point directly beneath the contact surfaces 549 of the adjacent arms 540A-H.

Hence, the'force of an expanding air-fuel charge ignited in the combustion chambers 525 will be directed inwardly toward the surfaces 549 on the adjacent arm 540 and the rotor 550, and a substantial torque force will be transmitted to the rotor 550. The chambers 525 are spherical to provide a low surface-to-volume ratio which allows complete combustion of the air-fuel charges in the chambers. The contact surface 549 on each of the arms 540 is provided with suitable sealing means, such as a poppet valve 128 or the labyrinth sealing grooves illustrated in the parent case, to seal the outlet channels 527 when the associated arm 540 is in its outermost position. Such seal allows the air-fuel charge to be sealed in the combustion chambers 525 for a selected time after ignition so that complete combustion will occur in the assembly 500.

The rotor housings 520 for each of the engine units 500A and B are also provided with a plurality of uniformly spaced transfer valves 200A-H, which are arranged adjacent each of the arms 540A-l-I in fluid communication with the associated compression chambers 522. The valves 200A-H have the same construction as described in connection with the single engine structure disclosed and claimed in the parent case. An intake passage 532 and manifold 533 (FIG. 6) connect the valves 200 to a suitable carburetor system (not shown) which feeds the engine assembly 500 with metered charges of a combustible air-fuel mixture at timed intervals. The valves 200 are moved to an opened position by rocker arms 231 and cam-operated lift rods 233 (FIG. 6) so that the inward movement of the associated arms 540 draws a charge of air-fuel mixture into the associated compression chamber 522. As described above, the valves 200 also open the compression chambers 122 after the compressed air-fuel charge has reached a selected pressure level.

The engine assembly 500 also includes means to transfer the compressed air-fuel charge from each compression chamber 522 through the valves 200 and into the axially aligned combustion chamber 525 in the opposite engine unit. To accomplish this, the central transfer housing 575 is provided with a plurality of transfer passages 535 leading from the valve assemblies 200 in each of the engine units 500A and B, in an axial direction, through the transfer housing 575 and into the aligned compression chamber 525A-H in the opposite engine unit. By this arrangement, the compression and combustion chambers in the engine units 500A and B are cross-coupled, and the units 500A and B will function in unison to provide a substantial torque force to the rotors 550 and the output shaft 530.

As illustrated in FIG. 6, each transfer passage 535 includes a spring-biased poppet valve 538 which normally closes the connected combustion chamber 525. The valves 538 are further arranged so that the force of the expanding charge in the combustion chamber 525 urges the valve 538 closed. However, the valves 538 are arranged to open in response to the pressure of the compressed air-fuel charges so as to permit the transfer of the compressed charge from the compression chambers 524 in one engine unit into the connected combustion chambers 525A-H in the other engine unit.

As illustrated in FIG. 5, the rotors 550A and B incorporated in the dual engine assembly 500 are doublelobe rotors. The rotors 550A and B control the sequence of movements of the four associated swinging arms 540 during the operation of the assembly 500. More specifically, the rotors 550A and B are designed to move opposed pairs of arms 540, such as the arms 540A and 540C, simultaneously with approximately simple harmonic motion. The double-lobe rotors 550A and B further cause the four associated arms 540A-D or 540E-H to complete two inward power strokes or cycles of operation for each revolution of the rotors, with the power strokes in the two engine units 500A and B overlapping in time.

Since the rotors 550A and B are identical, and are arranged in an axially aligned relationship on the shaft 530, only one of the rotors is illustrated in detail in FIG. 5. The periphery of each of the rotors 550A and B includes two symmetrical and diametrically opposed high dwell segments 554. As indicated by the positions of the arms 540B and D in FIG. 5, the rotor segments 554 sequentially engage with the four associated arms 540A-D or 540E-H and maintain the arms in their outermost positions for a time period defined by a selected degree of rotor rotation.

Furthermore, each of the rotors 550A and B include two symmetrical and diametrically opposed fall segments 556. The fall segments 556 are formed on the periphery of the rotors adjacent the high dwell segments 554 so as to engage each arm 540 immediately after the dwell segments 554. The segments 556 are shaped to engage the bevelled arm surfaces 543 and move the arms 540 inwardly with approximately simple harmonic motion during the power stroke for each arm. The rotor fall segments 556 thereby allow two charges to expand simultaneously against diametrically opposed arms (e.g., arms 540A and C) and the exposed portions of the rotor surface, to transmit a double power impulse to the shaft 530. The two opposed fall segments 556 also allow a charge to expand against each of the arms 540 and the exposed rotor portion twice for each revolution of the rotor 550.

The fall segments 556 of the rotors 550A and B terminate in low dwell segments 557. As illustrated in FIG. 5, the two low dwell segments 557 are diametrically opposed on the rotors 550A and B and are adapted to engage with the inwardly moving arms 540A-H to prepare the arms for a reversal of direction.

The remaining segments of the rotors 550A and B comprise rise segments 558 which engage the arms 540 immediately following the low dwell segments 557. The rise segments 558 are shaped to return the engaged arm 540 outwardly from its innermost position to its outermost position with substantially harmonic motion, as the rotors 550 rotate through a selected number of degrees. The above-described high dwell segments 554 then will engage the arms 540 and retain the arms in their outermost positions for a selected time period.

The engine units 500A and B also include means for exhausting the spent air-fuel from the interior of the rotor housings 520. In this regard, as illustrated in FIGS. and 6, the engine units 500A and B include a plurality of exhaust ports 590A-H; one portassociated with each of the arms 540A-H. The ports 590E-H are offset 45 degrees with respect to the ports 590A-D, re-

spectively, in FIG. 5. The exhaust ports 590A-H are in 5 fluid communication with an. exhaust passage 577 provided with the central transfer housing 575. The passage 577 connects the ports 590A-H to a suitable exhaust manifold system (not shown) which will conduct the exhaust gases from the engine units 500A and B.

The ports 590 are arranged in the engineunits 500A and B so that they are opened and closed by the associated rotors 550A and B. Thus, therotation of the rotor 550A will sequentially open and close the'ports 590A-D and bring successive segments of the interior of the associated rotor housing 520 into fluid communication with the exhaust passage 577. The same relationship exists between the rotor 550B and the ports 590E-I-I. Moreover, the ports 590AH are arranged in a pattern in the respective engine units 500A and B so that the ports are closed by the rotors 550 as the associated arms 540A-H, respectively, move inwardly against the adjacent rotor (e.g., the port 590A is closed .by the rotor 550A as the arm 540A moves inwardly). However, the rotation of the motors 550 sequentially opens the ports 590A-H before the associated arms 540A-H engage with the rise segments 558 of the rotor 550. This arrangement for the ports 590 and rotors 550 thereby assures that a port 590 (e.g., 590A) is opened before any outward movement of the associated arm 540 (e.g., 540A) starts to work against the spent combustion gases. A buildup of back pressure in the rotor housings 520, which would inhibit the operation of the engine assembly 500, is thus prevented.

In operation, the engine assembly 500 is started by cranking the flywheels 563 in the conventional manner so that the cam tracks 569 engage with the cam rollers 568 (FIG. 7). The tracks 569 and rollers 568 positively drive the arms 540A-H sequentially inward, against the fall segments 556 of the associated rotor 550A or B, and thereby draw charges of air-fuel mixture into the compression chambers 522. Then, the continued rotation of the rotors 550A and B engages the rotor rise segments 558 with the arms 540A-H and forces the arms sequentially outward to compress the air-fuel charges.

After a selected gas pressure is reached in the compression chambers 522, further outward movement of the arms 540 opensthe valves 200 and permits the compressed air-fuel charges to be transferred through the passages 535 into the cross-coupled compression chambers 525A-H in the opposite engine unit. The pressure of the compressed charge will also open the poppet valves 538 leading to the compression chambers 525.

More specifically, the charge compressed by the arm 540A is transferred to the combustion chamber 525E associated with the arm 540E in the opposite engine unit; the charge compressed by the arm 540B is transferred to the combustion chamber 525F associated with the arm 540F; the charge compressed by arm 540C is transferred to the combustion chamber 5256 of the arm 540G; and the charge compressed by the arm 540D is transferred to the combustion chamber 525H by the arm 540H. Similarly, during the operation of the engine assembly 500 the air-fuel charges compressed by the arm 540E are transferred to the combustion chamber 525D; the charge compressed by the arm 540F is transferred to the combustion chamber 525A; the charge compressed by the arm 540G is transferred to the combustion chamber 525B; and the charge compressed by the arm 540I-I is transferred to the combustion chamber 525C. The compression and combustion chambers of the opposed engine units 500A and B are thereby cross-coupled, and the units will operate in unison to transmit a continuous torque force to the output shaft 530.

Moreover, the operation of the engine assembly 500 is timed so that the arms 540 are closed against the outlet channels 527 for a selected time period, and thereby seal the compressed air-fuel charge in the associated combustion chamber 525. The rotors 550 hold the arms 540 in this extreme outward position for a period between approximately 45 and 60 of rotor rotation following ignition in the closed combustion chamber 525. By this arrangement, there will be substantially complete combustion of the air-fuel charges within the spherical combustion chambers 525 during the operation of the engine assembly 500.

After the air-fuel charges have burned in the chambers 525 for the desired interval, the continued rotation of the rotor 550 (induced by the flywheels 563 and the overlapping power strokes of the arms 540A-H) brings the fall segments 556 into association with the free ends of the arms 540. The charge will then expand against the adjacent arm and rotor, and impart a torque force to the rotor 550 and shaft 530. The associated exhaust port 590 remains closed by the rotor 550 as the expansion of the charge takes place in the rotor housing 520. Subsequently, further rotation of the rotor 550 through a predetermined arc opens the port 590, shortly before the associated arm 540 engages with the rise segment 558 on the rotor. As indicated by the positions of the arms 540A and C in FIG. 5, the rotation of the rotor 550 will then drive the engaged arms outwardly and force the spent air-fuel charge through the open exhaust port 590 (e.g., the ports 590A and 590C).

Due to the double-lobe configuration of the rotors 550A and B. each of the arms 540A-H will be driven through a complete cycle of operation twice for each revolution of the shaft 530. Thus, each arm 540A-H will have two inward power strokes for each shaft revolution. Moreover, the diametrically opposed arms in each of the engine units, such as the arms 540A and C in the unit 500A, will transmit their power strokes to the associated rotor 550 simultaneously. Since the units 500A and B are 45 out-of-phase on the shaft 530, these double power strokes of the opposed arms in one engine unit, such as the arms 540F and H in the unit 5008, will overlap the double power strokes of the arms in the opposed engine unit, such as the arms 540A and C in the unit 500A, by 45 of rotor rotation. The torque force applied to the shaft 530 by the arms 540A-H, hence, will be smooth and continuous.

Further, the double lobe rotors 550A and B and the dual engine units 500A and B provide the assembly 500 with a compact construction and a substantially high horsepower to weight ratio. In this regard, since the piston in a conventional reciprocating engine transmits a power stroke only once for every two revolutions of an associated shaft, the assembly 500, with 16 power strokes per shaft revolution (eight double strokes),.is substantially comparable to a 32 piston reciprocating engine. The assembly 500 is also statically and dynamically balanced and will operate with high thermal efficiency and substantially reduced exhaust emissions,

H Although the invention has been described above with a certain degree of particularity with respect to several embodiments, it should be understood that this disclosure has been made only by way of example. Consequently, numerous changes in the details of construction and in the combination and arrangement of the components as well as the possible mode of utilization for the rotaryengine power assembly in accordance with this invention will be apparent to those familiar with the art, and may be resorted to without departing from the scope of the invention.

I claim:

1. A rotary power assembly for transmitting a continuous torque force to a common output shaft comprising:

a housing surrounding a central output shaft and defining a pair of generally cylindrical rotor chambers having end walls;

a pair of rotors mounted in axial alignment on said common shaft, each of said rotors having a substantial transverse surface and side portions spaced adjacent said housing end walls;

a plurality of swinging arms pivotally mounted around the periphery of each of said rotor chambers and spaced uniformly with respect to the asso ciated rotor, with each of said arms having side portions spaced adjacent said housing end walls and a free arm end adapted to engage with the associated rotor surface;

the surface of each of said rotors including at least one first segment sequentially engageable with the free arm ends to permit said arms to move to an inward position and at least one second segment sequentially engageable with said free arm ends to return each of said arms to an outward position adjacent said housing;

a combustion chamber defined in said housing adjacent the free end of each of said arms in fluid communication with the associated rotor chamber and adapted to be closed by the adjacent free arm end when the adjacent arm is in its outward position and further adapted to permit a charge of combustion gases to expand inwardly into said rotor housing against the adjacent arm and the exposed portion of said rotor and thereby transmit a power impulse to the associated rotor and shaft;

exhaust means in fluid communication with each rotor chamber and arranged so that outward movement of said arms and the continued rotation of the associated rotor force spent charges of combustion gases from the rotor chambers through said exhaust means;

means sealing said side portions of said rotor and said arms with respect to said housing end walls;

an outwardly tapered horn member provided on each of said arms adjacent the free ends thereof and projecting outwardly into a generally conforming recess provided in the adjacent housing portion, each of said horn members having outwardly converging edges with one edge being positioned to slide in sealing engagement with said housing as said arms move between said inward and outward positions, so that said tapered horns prevent the creation of an engine-retarding partial vacuum force within said housing recesses, and further permit said recesses and swinging arms to define an expandable compression chamber associated with each arm which is sealed from said rotor housing by said horn member;

said rotor chambers being circumferentially offset with respect to each other to uniformly offset arms in one rotor chamber with respect to the arms in the other rotor chamber, with each compression chamber defined in each rotor chamber arranged in substantially axial alignment with one of said combustion chambers defined in the opposed rotor chamber; and

connecting means defining substantially short and unrestricted fluid transfer passages directly connecting each of said compression chambers to the axially aligned combustion chamber in the opposed rotor housing for transferring charges of compressed air-fuel mixture from said compression chambers into the connected combustion chambers in response to the sequential movement of said arms associated with said compression chambers, so that said compressed air-fuel charges are conditioned for expansion within said combustion chambers to create sequential power impulses against the rotors and arms associated with said combustion chambers;

whereby said dual engine units operate as an integral power assembly, having reduced internal fluid losses, which transmits a smooth and continuous torque force to said shaft through said uniformly spaced arms.

2. A rotary power assembly for transmitting continuous torque force to a power output shaft means comprising:

a housing surrounding said output shaft means and defining a pair of generally cylindrical rotor chambers having end walls;

a pair of double-lobe rotors mounted in a predetermined arrangement on said output shaft means, each of said rotors being positioned within one of said rotor chambers and having a substantial transverse surface and side portions spaced adjacent said end walls;

four swinging abutment arms pivotally mounted around the periphery of each rotor chamber and spaced uniformly with respect to the associated rotor, with each of said arms having side portions spaced adjacent said end walls and a free arm end adapted to engage with the associated rotor surface;

the surface of each of said rotors defining a pair of first rotor segments adapted to sequentially engage with the free arm ends of a pair of opposed arms and permit said engaged arms to move to an inward position with respect to the engaged rotor and thereby transmit a torque force to said engaged rotor and said shaft means;

the surface of each of said rotors further defining a pair of second rotor segments sequentially engageable with the free ends of a pair of opposed arms to return said engaged pair of arms to an outward position;

an outwardly projecting sealing member provided on each of said arms and projecting outwardly into a generally conforming recess provided in the adjacent housing portion, each of said sealing members being positionedto slide in sealing engagement with said housing as said arms move between said inward and outward positions, said sealing members and housing defining an expandable compression chamber outwardly adjacent each arm which is sealed from said rotor housing, with said sealing members and housing cooperating to prevent the creation of an engine-retarding partial vacuum force within said housing recesses;

a combustion chamber defined in said housing adjacent the free end of each of said arms in fluid communication with the associated rotor chamber and adapted to be closed by the adjacent free arm end when the adjacent arm is in its outward position and further adapted to permit a charge of combustion gases to expand inwardly into said rotor housing against the adjacent arm and the exposed portion of said rotor and thereby transmit a power impulse to the associated rotor and shaft;

exhaust means in fluid communication with each rotor chamber and arranged so that outward movement of said arms and the continued rotation of the associated 'rotor force spent charges of combustion gases from the rotor chambers through said exhaust means;

means sealing said side portions of said rotor and said arms with respect to said housing end walls; and

connecting means defining fluid transfer passages directly connecting each of said compression chambers to a combustion chamber in the opposed rotor chamber for transferring charges of compressed air-fuel mixture from said compression chambers in one rotor chamber into the connected combustion chambers in the other rotor chamber in response to the sequential movement of said arms associated with said compression chambers, so that said compressed air-fuel charges are conditioned for expansion within said combustion chambers to create sequential power impulses against the rotors and arms associated with said combustion chambers;

whereby said arms and rotors operate as an integral power assembly which creates four double power impulses to each rotor per rotor revolution and thereby transmits 16 spaced power impulses to said power shaft means per revolution.

3. A rotary power assembly in accordance with claim 2 wherein said pair of rotor chambers are circumferentially offset with respect to each other by approximately 45 to uniformly offset said arms in one rotor chamber with respect to the arms in the other rotor chamber and thereby cause said arms to transmit uniformly spaced power impulses to said power shaft means, said offset rotor chambers further positioning each of said compression chambers in substantially axial alignment with the one of said combustion chambers defined in the opposed rotor chamber, with said connecting means defining short and substantially axially-directed fluid transfer passages directly connecting each of said compression chambers to the aligned combustion chamber, so that said compressed air-fuel charges are transferred from said compression chambers to said combustion chambers with minimized flow velocity and low internal fluid friction losses.

4. A rotary power assembly in accordance with claim 2 wherein said combustion chambers are spherical in configuration to provide a low surface-to-volume ratio and further wherein said sealing member provided on each of said arms comprises an outwardly tapered horn member having outwardly converging edges, with one edge being positioned to slide in sealing engagement with said housing as said arms move between said inward and outward positions. 

1. A rotary power assembly for transmitting a continuous torque force to a common output shaft comprising: a housing surrounding a central output shaft and defining a pair of generally cylindrical rotor chambers having end walls; a pair of rotors mounted in axial alignment on said common shaft, each of said rotors having a substantial transverse surface and side portions spaced adjacent said housing end walls; a plurality of swinging arms pivotally mounted around the periphery of each of said rotor chambers and spaced uniformly with respect to the associated rotor, with each of said arms having side portions spaced adjacent said housing end walls and a free arm end adapted to engage with the associated rotor surface; the surface of each of said rotors including at least one first segment sequentially engageable with the free arm ends to permit said arms to move to an inward position and at least one second segment sequentially engageable with said free arm ends to return each of said arms to an outward position adjacent said housing; a combustion chamber defined in said housing adjacent the free end of each of said arms in fluid communication with the associated rotor chamber and adapted to be closed by the adjacent free arm end when the adjacent arm is in its outward position and further adapted to permit a charge of combustion gases to expand inwardly into said rotor housing against the adjacent arm and the exposed portion of said rotor and thereby transmit a power impulse to the associated rotor and shaft; exhaust means in fluid communication with each rotor chamber and arranged so that outward movement of said arms and the continued rotation of the associated rotor force spent charges of combustion gases from the rotor chambers through said exhaust means; means sealing said side portions of said rotor and said arms with respect to said housing end walls; an outwardly tapered horn member provided on each of said arms adjacent the free ends thereof and projecting outwardly into a generally conforming recess provided in the adjacent housing portion, each of said horn members having outwardly converging edges with one edge being positioned to slide in sealing engagement with said housing as said arms move between said inward and outward positions, so that said tapered horns prevent the creation of an engine-retarding partial vacuum force within said housing recesses, and further permit said recesses and swinging arms to define an expandable compression chamber associated with each arm which is sealed from said rotor housing by said horn member; said rotor chambers being circumferentially offset with respect to each other to uniformly offset arms in one rotor chamber with respect to the arms in the other rotor chamber, with each compression chamber defined in each rotor chamber arranged in substantially axial alignment with one of said combustion chambers defined in the opposed rotor chamber; and connecting means defining substantially short and unrestricted fluid transfer passages directly connecting each of said compression chambers to the axially aligned combustion chamber in the opposed rotor housing for transferring charges of compressed air-fuel mixture from said compression chambers into the connected combustion chambers in response to the seqUential movement of said arms associated with said compression chambers, so that said compressed air-fuel charges are conditioned for expansion within said combustion chambers to create sequential power impulses against the rotors and arms associated with said combustion chambers; whereby said dual engine units operate as an integral power assembly, having reduced internal fluid losses, which transmits a smooth and continuous torque force to said shaft through said uniformly spaced arms.
 2. A rotary power assembly for transmitting continuous torque force to a power output shaft means comprising: a housing surrounding said output shaft means and defining a pair of generally cylindrical rotor chambers having end walls; a pair of double-lobe rotors mounted in a pre-determined arrangement on said output shaft means, each of said rotors being positioned within one of said rotor chambers and having a substantial transverse surface and side portions spaced adjacent said end walls; four swinging abutment arms pivotally mounted around the periphery of each rotor chamber and spaced uniformly with respect to the associated rotor, with each of said arms having side portions spaced adjacent said end walls and a free arm end adapted to engage with the associated rotor surface; the surface of each of said rotors defining a pair of first rotor segments adapted to sequentially engage with the free arm ends of a pair of opposed arms and permit said engaged arms to move to an inward position with respect to the engaged rotor and thereby transmit a torque force to said engaged rotor and said shaft means; the surface of each of said rotors further defining a pair of second rotor segments sequentially engageable with the free ends of a pair of opposed arms to return said engaged pair of arms to an outward position; an outwardly projecting sealing member provided on each of said arms and projecting outwardly into a generally conforming recess provided in the adjacent housing portion, each of said sealing members being positioned to slide in sealing engagement with said housing as said arms move between said inward and outward positions, said sealing members and housing defining an expandable compression chamber outwardly adjacent each arm which is sealed from said rotor housing, with said sealing members and housing cooperating to prevent the creation of an engine-retarding partial vacuum force within said housing recesses; a combustion chamber defined in said housing adjacent the free end of each of said arms in fluid communication with the associated rotor chamber and adapted to be closed by the adjacent free arm end when the adjacent arm is in its outward position and further adapted to permit a charge of combustion gases to expand inwardly into said rotor housing against the adjacent arm and the exposed portion of said rotor and thereby transmit a power impulse to the associated rotor and shaft; exhaust means in fluid communication with each rotor chamber and arranged so that outward movement of said arms and the continued rotation of the associated rotor force spent charges of combustion gases from the rotor chambers through said exhaust means; means sealing said side portions of said rotor and said arms with respect to said housing end walls; and connecting means defining fluid transfer passages directly connecting each of said compression chambers to a combustion chamber in the opposed rotor chamber for transferring charges of compressed air-fuel mixture from said compression chambers in one rotor chamber into the connected combustion chambers in the other rotor chamber in response to the sequential movement of said arms associated with said compression chambers, so that said compressed air-fuel charges are conditioned for expansion within said combustion chambers to create sequential power impulses against the rotors and arms associated with said combustion chambers; whereby said arms and rotors operate as an integral power assEmbly which creates four double power impulses to each rotor per rotor revolution and thereby transmits 16 spaced power impulses to said power shaft means per revolution.
 3. A rotary power assembly in accordance with claim 2 wherein said pair of rotor chambers are circumferentially offset with respect to each other by approximately 45* to uniformly offset said arms in one rotor chamber with respect to the arms in the other rotor chamber and thereby cause said arms to transmit uniformly spaced power impulses to said power shaft means, said offset rotor chambers further positioning each of said compression chambers in substantially axial alignment with the one of said combustion chambers defined in the opposed rotor chamber, with said connecting means defining short and substantially axially-directed fluid transfer passages directly connecting each of said compression chambers to the aligned combustion chamber, so that said compressed air-fuel charges are transferred from said compression chambers to said combustion chambers with minimized flow velocity and low internal fluid friction losses.
 4. A rotary power assembly in accordance with claim 2 wherein said combustion chambers are spherical in configuration to provide a low surface-to-volume ratio and further wherein said sealing member provided on each of said arms comprises an outwardly tapered horn member having outwardly converging edges, with one edge being positioned to slide in sealing engagement with said housing as said arms move between said inward and outward positions. 